The U.S. has just announced a new security and defense assistance package for Ukraine valued at $400 million. Among spare parts, ammunition, and missile supplies there is a new measure intended to combat the enemy drones: heavy machine guns.
The exact model (or models) of these machine guns have not been specified yet.
The U.S. Army has several models of automatic large-caliber guns. Defense Express provides an assumption that these weapons could be the M134 or GAU-19. Both of them are rotary models with a high firing rate which from a technical perspective is the most feasible way to deal with UAVs within a short time frame.
Rotary machine guns are indeed very often used in the anti-aircraft role, including a very popular rotary autocannon M61 Vulcan with a caliber of 20 mm which is typically mounted on attack aircraft.
In the case of machine guns, the caliber is lower. The U.S. Army typically uses 12.7 mm and 7.62 mm calibers. In order to counter drones, the caliber size is not that much important, as in most cases a single bullet is enough to critically hit small aircraft. But to make the targeting process easier, a high rate of fire is a very convenient parameter for soldiers.
M134 Minigun with a NATO 7.62×51 mm caliber is a medium gun that perhaps does not fall under the “heavy machine gun” classification, but it could be easily used by the Ukrainian Armed Forces to combat Russian and Iranian drones.
The GAU-19 is somewhat less-known, but features a larger .50 BMG caliber (12.7×99 mm), making it efficient against even larger aircraft or light-armored ground vehicles.
Both M134 and GAU-19 can be fitted with thermal imaging devices. M134 Minigun can fire up to 6 thousand rounds per minute, while GAU-19 shoots up to 2 thousand rounds per minute. In terms of fire rate, M134 7.62×51 could be an even better option against such targets as Shahed-136 or the ZALA Lancet loitering munitions.